Regulating local electron transfer environment of covalent triazine frameworks through F, N co-modification towards optimized oxygen reduction reaction

Abstract

The high conductivity of electrocatalyst can eliminate the Schottky energy barrier at the interface of heterogeneous phases during an electrocatalytic reaction and accelerate the rapid electron transfer to the catalytic active center. Therefore, the electronic conductivity is a vital parameter for oxygen reduction reaction (ORR). Covalent triazine frameworks (CTFs) have shown great potential application as electrocatalysts in ORR with a merit of the diverse building blocks. However, the intrinsic low conductivity and high impedance of CTFs could be significant setbacks in electrocatalytic application. Herein, CTFs were constructed by introducing F and N co-modification for efficient 2e⁻ ORR. Compared with the pristine CTF, the co-presence of F, N could increase the conductivity obviously by 1000-fold. As a result, F-N-CTF exhibits enhanced catalytic performance of H₂O₂ generation and selectivity towards reaction pathways. This work reveals the importance of conductivity optimization for CTFs and provides guidance for designing high conductivity non-metallic organic semiconductor catalysts for 2e⁻ ORR.